Valve



Aug.' 20, 1929. 1. A. TILDEN VALVE Filed June"20. 1926 l Z NT. 1 Wb Z W7 w M 1 y, 0 www z M H 4 mf.

Patented Aug. 20, 1929.

UNITED STATES PATENT OFFICE.

I JAMES A. TILDEN, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO HER'SEYMANUFAC- TURING COMPANY, OF SOUTH BOSTON, MASSACHUSETTS, A CORPORATIONOF MAS- SACHUSETTS.

VALVE.

Application filed .Tune 30,

This invention relates to valvesand is illustrated as embodied in ahydraulic check valve of the back pressure type suitable for use, forexample, to by-pass small quantities from a fire supply main. It will beunderstood, however, that the invention is not restricted to such a usenor is it, in some of its features, restricted to use in that type ofvalve.

Check valves of the back pressure type are used, for example, in watermains furnishing a potential supply at full head for lire purposes inorder that, when the valves are closed, they shall deflect or direct thewater through other channels such as by-passes around the valves. Such aby-pass may iiiclude a suitable meter to allow the use and measurementof small quantities drawn from the main for other than fire purposes, atgreatly reduced head. To this end, it is desired that such valves shalloffer a predetermined and substantial resistance to opening and shall beso constructed that, once opened by a large demand, they shall offer aminimum resistance to the flow of water so that they shall not cause areduction of head at a time when it is most needed. y

An object of the present invention is to provide an improved check valveorganized to offer a delinite and considerable resistance to themovement or initial opening of the valve under ordinary pressures.

Check valves are frequently gravity operated and the difliculty ofproviding, within the limits of good design, a suilicient single weivhtto control a movable valve'member leadas to the employment of compoundweights, acting together' upon a single valve member. A further objectof the invention is to provide a compact and eicient check valve of thecompound weighted type,

In accordance with features of the invention, in order that a maximumresistance shall be offered to opening and only a minimum resistanceoffered once the valve has started to open, the illustrated constructionprovides a valve member and a supplemental weighted member compoundedthrough a leverage con structed and arranged so that even a smallopening movement of the valve member causes a considerable movement ofthe supplemental weighted member and hence so that the latter memberbecomes substantially ineffective after a small fractional part of the1926. 'serial No. 119,657.

total displacement of the movable valve member has taken place.

These and other features of the invention are set forth in the claimsand have been more fully described in the following speciication,reference being had to the'accolnpanying drawings, in which y y Fig. 1is a longitudinal section throuffh the valve casing showing the valve inclosed position, and

Fig. 2 is a similar section taken with the valve in fully openedposition, showing in dotted lines the critical intermediate position atwhich the supplemental member is rendered substantially ineffective.

The movable member or flap 10 of the valve is pivotally mounted tocontrol the passage through a valve casing 12 having external flanges 14andl by means of which it may be inserted in the water main the'flowthrough which it is desired to control. This casing has an internalflange 18 in which there is threaded a sleeve 20 having a seat surface22 and provided with upstanding lugs 24 between Which is pivoted thecarrier 26 of the fla 10.

n order that the Hap 10 ma automatically close the passage through t ecasing 12 when it is not opened and held open by the flow of water, thecarrier 26 is pivoted about a horizontal rod 28 in the lugs 24 at theupper part of the casing so that it will be closed by its own weight,adjustably redetermined by the addition or removal o some heavy materialsuch as lead 30 in the pocket 32 of said carrier. Actual closure of thepassage is effected by a disk-shaped valve member 34 reinforced byradial ribs 36 and loosely supported in the carrier 26 by a stud 38passing through a doubly tapered hole 40 where it is held by nuts 42 andcotter pin 44. This valve member 34 has an annular'groove upon its facein which a soft rubber Washer 46 is held by means of a smaller disk 48pressed against the washer and held there by locked nuts upon anotherstud 5() opposing the stud 38 upon the valve member. Thus a, softresilient surface is provided upon the Avalve member 34 and the latteris self-adjustin so an auxiliary weighted lever 56 having lateral armsby means of which it is pivotally supported upon a horizontally disposedrod 58 extendingparallel to the rod 28 at the other side of the upperpart of the casing so that the auxiliary lever overhangs the arm 54 ofthe valve carrier. The outer surface 60 of the supplemental weightedlever 56 is shaped like and lies substantially parallel to the adiacentinner surface of the corresponding part of the dome 52 to obtain thedesired weight in a minimum space. This weightedr auxiliary lever 56.swinging in the opposite sense from the flap l0 to con-serve space andfurther to reduce the necessary sizeof the dome 52, is arranged tooverhang said valve member and to bear against a roller 62 mountedcentrally atV the end of the arm 54 upon the valve carrier in allpositions of the parts. Such a centralized rolling' contact avoidsuneven pressure or twistinswith the resultant bearing friction. Theroller is pivotally mounted upon a pin 64; surrounded bv a hard rubberbushing 66. The hard rubber bushing 66 prevents corrosion of the bearingbetween the roller and the pivot and is self-lubricated by the action ofthe surroundingr water.

The under side of the weighted lever 56 is recessed slightly to receivea central shoe 68 ,slightly wider than the roller 62. The face of thisshoe is curved for the greater portion of its length so that, when thevalve is in open position asin 2, the center of the curve coincides withthe center of the pivot rod 28. A t the end of the shoe nearer the pivotrod 58, howeventhe shoe is recessed or cut away at 70 to provide ashoulder 7 2 under which the roller 62 must ride as the valve lifts saidauxiliary lever 56 when it attempts to move from closed to openposition. As the valve starts to'open, such movementis opposed not onlyby the weight ofthe flap l0 itself including the enclosed weight 3() butis additionally opposed by the full effect of the weighted lever 56 asits shoulder 72 bears against the lever arm 54 upon the valve carrier 26to resist its opening movement. Further it will bc. noted that movementof the roller 62m emerging from .the recess 70 of lthe shoe isetfectiveito move the weighted l lever'56 through practically its wholerange of movement to an upright position in which it is only slightlyunbalanced. The passage of the roller under the shoulder 72 upon thesh'oe'68is marked by an automatic increase in the eifectivelength of thelever arm 54 as the point of contact upon the roller turns away fromthe'pivotY rod 28. Just as soon. as the roller 62 has passed theshOulder 72 and reached a point suchas 74 upon the curved surfacefof theshoe 68, it holds the weighted lever 56 in the upright and substantiallyineffective position to which it has been moved Y and in which anypressure exerted by said wei ehted lever, acting in a direct linethrough the pivot 28, has no closing effect upon the valve member l0,and further movement of the valve member under pressure of the water isresisted only by its own weight.

For the salte of a concrete example of one particular use of my checkvalve, let us assume that the valve casing l2 has been inserted in thefire supply main of a large factory and that a bypass is provic dconnecting the passages 8O and 82 at opposite sides of the valve. Asuitable meter (not shown)V of small capacity usually included in theby-pass which is capable of measuring such small quantities as may bedrawn for nonemergency purposes. My valve, in common with all suchvalvesof the baclrpressure type, will be maintained in its closedposition partly by the action of its weights but more especially by thebalancing effect of the hydrostatic pressure against the right-hand sideof the valve member. his condition of equilibrium will continue untilthe demand, or chance for expansion of the water upon the right side,increases to a point where there is aY substantial diminution of theheadupon 'this side, causing an unbalanced condition.

The capacity of the by-pass is not enough to allow a drop in pressureupon the outgoing or right side of the valve when small quantitles arebeing drawn sufiicient to unbalance and open the valve., This allows theuse of this source of supply to a limited extent by the factory forcommercial purposes, such use being measured and paidfor. lhen, however,a demand arises for a considerable quantity, as in case of a lire, thedrop in hydrostatic pressure upon the right side creates an unbalancedcondition which starts the opening of the valve. lt will be noted thatthe valve is so constructed that a very considerable and predetermineddifference of pressures must exist before the combined effects of thewein ts 30 and 56, acting through their lever aims, will be overcome. Assoon the movement of the valvemember is sufiicient to carry the roller62 past the shoulder 72, thereby lifting the a m:iliary weighted leverv56 to upright posi n in which it is ineffective. the latter will, be.held in such ineffective relation as the roller 62 moves along thecurved surface of the shoe 68. valve flap l() may thenbe readily pushedout Vof the direct path of the flowing water so that The Havingdescribed the invention, what I claim as new and desire to secure byLetters Patent of the United States is:

1. In combination, a self-closing valve member arranged to offer adefinite resistance to displacement from one position, and supplementalmeans bearing against said member in all positions constructed andarranged to superimpose a predetermined additional resistance againstthe initial displacement of said member until after a fractional part ofthe total displacement has been passed and then-to remain in slightlyunbalanced condition imposing only a slight resistance and permittingsubstantially free movement of said valve member to its position ofmaximum opening.

2. In combination, a pivotally mounted flap check valve member arrangedto be moved to closed position by its own weight, a pivotally mountedsupplemental weighted member normally holding said valve shut, and aroller disposed substantially midway of one member bearing upon anintermediate part of the other member, said members being constructedand arranged so that said valve member will move said supplementalweighted member to a substantially ineffective position by means of arelatively small opening movement of said valve member.

3. In combination, a check valve of the back pressure type having apivoted valve member, and a weighted lever arranged to assist in holdingsaid valve member in one position, said lever having a curved bearingsurface provided with a shoulder at one end whereby the lever issubstantially ineffective when the curved surface is in contact with thevalve member and is effective when the shoulder is in contact therewith.

4. In combination, a valve casing, a depending valve member and acooperating overhanging weighted member pivoted on substantiallyparallel horizontal axes near the upper part of the casing, and meansextending outwardly from said valve member to bear against said weightedmember at a point near the pivot of the latter when the valve is inclosed position, said means and weighted member being constructed andarranged so that a small opening movement of the valve member iseffective to move said Weighted member to an upright position where itis substantially ineffective.

5. In combination, a valve casing provided with a passage having aninlet opening and a discharge opening'and a dome extending outwardlyfrom the passage therebetween, a pivotally mounted valve member arrangedto control said passage and tending to close under the action of its ownweight, and a weighted auxiliary lever coacting with said valve memberto assist its closing action, said lever being pivotally mounted torotate within said dome in the opposite sense from the valve member andto maintain Contact with said valve'member in all positions as itcooperates therewith to assist in closing said valve member whereby thesize of the dome necessary to house the valve member and the auxiliarymember is reduced.

6. In combination, a pivotally mounted valve member depending from ahorizontal pivot, said valve member being provided with an arm extendingoutwardly substantially horizontally when said valve member is closed,and a pivotally mounted auxiliary weight overhanging said arm andbearing against the outer end of the arm thereby to assist in closingsaid valve member, said valve member and said weight being rotatable inopposite senses as the valve opens and closes.

7. In combination, a depending pivoted valve member having an outwardlyextending arm provided with a terminal roller, and an auxiliary weightedlever overhanging said arm and provided with a shoulder near its pivotalmounting bearing against said roller when the valve member is in closedposition whereby a small opening movement of the valve member will causea relatively large movement of the weighted lever so that a considerableforce is required to start the valve to o en. l

I)8. In combination, a casing having a valve seat, a pivotally mountedvalve member and an auxiliary weighted lever in said casing normallyoverlying and resting against said valve member tending to hold it shutagainst said seat, said auxiliary lever having a curved bea-ring surfacefor Contact with the valve member when the valve is open, and a shoulderadapted to bear on the valve member when closed to resist the openingmovement of the valve member.

9. In combination, a pivotally mounted valve member and a cooperatingoverhanging pivoted weighted member bearing against and tending to closethe valve member, said members having coacting portions serving as leverarms and being constructed and arranged automatically to increase theeffective length of one lever arm by movement of the valve member awayfrom closed position.

10. In combination, a casing having a passage and a valve seat therein,a pivotally mounted flap valve arranged to hang against said seat toclose said passage, a pivoted weight in said casing overhanging saidvalve and bearing against it to assist in holding it closed, andconnections between said valve and said Weight constructed and arrangedto cause a small opening movement of said flap valve to move said weightto an upright substantially ineffective position Where it is onlyslightly unbalanced.

In testimony whereof I have signed my name to this specification.

JAMES A. TILDEN.`

